The Solidity Contract-Oriented Programming Language

Solidity is an object-oriented, high-level language for implementing smart contracts. Smart contracts are programs which govern the behaviour of accounts within the Ethereum state.

Solidity is a curly-bracket language designed to target the Ethereum Virtual Machine (EVM). It is influenced by C++, Python and JavaScript. You can find more details about which languages Solidity has been inspired by in the language influences section.

Introduction to Smart Contracts A Simple Smart Contract Let us begin with a basic example that sets the value of a variable and exposes it for other contracts to access. It is fine if you do not understand everything right now, we will go into more details later.

Solidity Example Hello World

A "Hello World" program in Solidity is of even less use than in other languages, but still:

// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.9.0;

contract HelloWorld {
    function helloWorld() external pure returns (string memory) {
        return "Hello, World!";
    }
}

Introduction to Smart Contracts

A Simple Smart Contract

Let us begin with a basic example that sets the value of a variable and exposes it for other contracts to access. It is fine if you do not understand everything right now, we will go into more details later.

Storage Example

// SPDX-License-Identifier: GPL-3.0
pragma solidity >=0.4.16 <0.9.0;

contract SimpleStorage {
    uint storedData;

    function set(uint x) public {
        storedData = x;
    }

    function get() public view returns (uint) {
        return storedData;
    }
}